Bacteria colonies can increase by [tex]$73 \%$[/tex] every 2 days. If you start with 150 bacteria microorganisms, how large would the colony be after 8 days?

Future Amount [tex]$= I (1+r)^{ t }$[/tex]

Future Amount [tex]$=[?]$[/tex] microorganisms



Answer :

To solve this problem, we need to calculate the future amount of bacteria after 8 days, given that the colony increases by 73% every 2 days.

We will use the formula for exponential growth:

[tex]\[ \text{Future Amount} = I \left(1 + r\right)^{ t } \][/tex]

where:
- [tex]\( I \)[/tex] is the initial amount of bacteria,
- [tex]\( r \)[/tex] is the growth rate in decimal form,
- [tex]\( t \)[/tex] is the time period measured in the number of growth periods.

First, let's identify the values from the problem:
- The initial amount of bacteria [tex]\( I \)[/tex] is 150.
- The growth rate [tex]\( r \)[/tex] is 73%, which can be written as 0.73 in decimal form.
- The total number of days is 8 days.
- The growth period is every 2 days.

Next, we need to determine the number of growth periods within the given time frame.

[tex]\[ \text{Number of growth periods} = \frac{\text{Total number of days}}{\text{Growth period}} \][/tex]

Substitute the values:

[tex]\[ \text{Number of growth periods} = \frac{8}{2} = 4 \][/tex]

This means the bacteria colony will grow 4 times in 8 days. Now, we can apply these values to our formula:

[tex]\[ \text{Future Amount} = 150 \left(1 + 0.73\right)^{4} \][/tex]

Calculate the growth factor:

[tex]\[ 1 + 0.73 = 1.73 \][/tex]

Raise the growth factor to the power of the number of growth periods:

[tex]\[ 1.73^4 \][/tex]

Now, multiply this result by the initial amount of bacteria (150):

[tex]\[ \text{Future Amount} = 150 \times 1.73^4 \approx 150 \times 8.95745 = 1343.6175615 \][/tex]

Therefore, after 8 days, the bacteria colony will have grown to approximately 1343.62 microorganisms.

[tex]\[ \text{Future Amount} \approx 1343.62 \text{ microorganisms} \][/tex]